Basis of Presentation and Summary of Significant Accounting Policies - Insurance Subsidiary (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	$ 55.0	$ 54.7
Other Current Liabilities
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	13.0	13.1
Other Noncurrent Liabilities
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	$ 42.0	$ 41.6